Folding and collapsible ladders

ABSTRACT

A folding and collapsible ladder wherein the rungs are pivotally attached to the side rails and adjacent rungs are attached to the side rails in different planes, i.e., adjacent rungs are offset. To collapse or fold the ladder into a narrow but slightly longer mass, the rungs fold down like a closing parallelogram until the rungs are substantially parallel to the side rails. Rigidity of the ladder is provided by one or more braces pivotally attached at one end to one side rails and the opposed end of the braces provided with fastening means to removable secure the braces to the other side rail.

United States Patent Lauring Mar. 27, 1973 {54] FOLDING AND COLLAPSIBLE258,186 5/1882 Winters ..182/159 LADDERS 2,875,935 3/1959 Bultermore..182/160 [76] lnvemor' x i ggga tai i g- 2 251 Primary ExaminerReinald0P. Machado Fans, Minn 56649 1 AttorneyH. F. Woodward [22] Filed: Mar.18, 1971 57 TR I 1 pp 1251689 A folding and collapsible ladder whereinthe rungs are pivotally attached to the side rails and adjacent rungs521 11.5. c1 ..182/159, 182/178 are attached to the Side rails indifferent Planes, [51] 0 adjacent rungs are offset. To collapse or foldthe {58] Field of Search ..182/160, l59,95,96 ladder imo a narrow butSlightly longer mass, the rungs fold down like a closing parallelogramuntil the [56] References Cited rungs are substantially, parallel to theside rails. Rigidity of the ladder is provided by one or more bracesUNITED STATES PATENTS pivotally attached at one end to one side railsand the 453,929 6/1891 Heister 182 160 pp end Of the braces Providedwith fastening 3,517,770 6/1970 Loix ..l82/96 means to removable securethe braces to the other 1,887,301 11/1932 Gordon ..182/159 Side rail.

355,574 1/1887 Tilley 1 ..182/178 2,962,] 13 11/1960 Heimlicher 182/1603 Claims, 10 Drawing Figures FOLDING AND COLLAPSIBLE LADDERS Thisinvention relates to a folding ladder of the type of having a pair ofside rails, collapsibly secured together and in which the side railspivotally supports a series of spaced-apart rungs adapted to be securedin an operative position.

It is an object of the present invention to make a collapsible ladderconstruction in which the adjacent rungs are in different planes, i.e.,offset from each other, and means being provided for locking or bracingthe rungs in a parallel spaced-apart position, and which can be easilydisengaged when desirable to fold or co]- lapse the ladder by closingthe rails upon one another.

These and other objects and novel features will be more fullyappreciated from the following description of preferred embodiments ofthe invention selected for purposes of illustrations and shown in theaccompanying drawings in which:

FIG. 1 is a front elevational view of the novel folding or collapsibleladder:

FIG. 2 is a fragmentary view of the ladder fully col- 7 lapsedcondition:

FIG. 3 is an end view showing brackets for pivotally attaching ladderrungs to the side rails:

FIG. 4 is a view of the ladder, with parts broken away, showing use ofopposed channel bars for the side rails:

FIG. 5 is a view similar to FIG. 4 in which the side rails are channelbars with middle web or two channel bars secured together for siderails:

FIG. 6 is a view of the folding ladder, with parts broken away, showingsolid material as side rails:

FIG. 7 is an end view of solid side rails showing two rows of rungs indifferent plan or offset each other:

FIG. 8 is a side view of an extension to be used with the foldingladder:

FIG. 9 is a front view, with parts broken away, showing folding ladderwith folding extension: and

FIG. 10 is a side view showing the folding extension used with foldingladder to provide a self supporting ladder.

In the structures shown in the drawings numerals l0 and 12 denote siderails of wood, magnesium, aluminum, or any suitable material. The siderails 10 and 12 may be of any desired dimensions, and may be solidmaterial as shown in FIGS. 1, 2, 6 and 7, or may be in the form ofchannel bars as generally indicated at 26 and shown in FIG. 4, ormodified channel bars as indicated at 28 and shown in FIG. 5. Braces 14are provided between side rails as shown in FIGS. 1 and 9. It beingunderstood that any suitable bracing means may be used, for example,brace shown in FIG. 80f U.S. Pat. No. 2,727,671 and as shown in FIG. 1of U.S. Pat. No. 1,341,707.

The novel arrangement of parts which provide a way to fold or collapse aladder so that it occupies a minimum of space. The folding isaccomplished by offsetting or positioning in different planes, everyother rung 16 so that they fold by each other. The rungs 16 are in aplurality of rows and are pivotally at 18 and 20 where they are attachedto the ladder side rails 10 and 12. The-rungs can fold down like aclosing parallelogram until the rungs become substantially parallel tothe side rails.

The folded length of the ladder becomes longer by approximately thelength of a rung. The thickness of the folded ladder may be as low asthe thickness of the side rails.

Rigidity of the ladder is provided by suitable brace or braces 14. InFIGS. 6 and 9 diagonally cross members form the bracing effect. One endof braces 14 is hinged at 19 and 21 where they are attached to the siderails 10 and 12', and the other ends of the braces 14 are provided withsuitable fastening devices 22 and 24 for remobile attaching them to siderails 10 and 12. The fastening devices in a simple form may be aself-locking snap-in pin in a hole in the side rails. When the ladder isin the folded position the diagonal braces 14 are folded down along theedge of the side rail to which it is attached. It is to be understoodthat a locking mechanism may be placed on the end or ends of each rungfor providing rigidity to the folding ladder. The rungs may be made ofwood, metal, composition, solid or hollow and in suitable geometricshape to provide strength.

The ladder may be of any practicable length and extra sections may beattached to give the desired length. The ladder sections may vary inwidth whereby the equivalent ofa tapered ladder is provided.

In FIG. 3 are shown one means of pivotally attaching rungs 16 to theside rails 10 and 12. This means includes generally U-shapedcross-section and having their bottoms sections 26 solidly secured tothe side rails 10 and 12. If desired U-shaped means may be constructedas an integral part of the side rails of the types shown in FIGS. 4 and5. The rungs 16 have their end portions journaled on the shafts 28.Spacers 30 between the rungs l6 and the flanges 32.

As shown in FIGS. 4 and 5 the channel-like members have bottoms, sidewalls extending outwardly from the bottoms and rib-like membersextending longitudinal of each channel and parallel to the side walls.The rib does not extend outwardly a distance greater than the sidewalls/The ribs may be interrupted between areas of rung attachments (SeeFIG. 4).

If additional section are to be employed to make a longer ladder, one ofthe extensions as shown in FIG. 8 is made as shown and is narrower thanthe first section. Aperatures or openings 33 and 34 are provided in oneend of the extensions side rails. If desirable locking devices or pins36 may be used to secure the sections of the ladder together. In use theextension, in the most extended position, the bottom part thereof shouldhave the top rung of the ladder fit into the openings 33 and tiallyequal to distance between adjacent rungs in the first section of theladder.

In FIG. 10 is shown the novel ladder and an extension used as a selfsupporting IadderJWhen the ladder. is used in this manner a removablebraces 38 are used and a modified rung receiving means 40 is provided.In

this use and some other uses the extension section only may 'not havethe rungs off-set, but in casses the rung spacing must be greaterthanthe length of the rungs to nel-like members side rails; each of saidrails having bottom, outwardly extending side walls and longitudinalextending rib-like member projecting from the bottom and beingsubstantially parallel to side walls; one section of said ladder havingone end of each channel-like side rails provided with one wall, part ofbot tom and rib, extending the distance between-adjacent rungsin theother section, beyond the remainder of bottom and other sidewall, thebottoms of unequal length having rung receiving openings therein; rungspivotally attached to side walls and ribs, adjacent rungs at-least inone section attached to side walls and ribs in different planes wherebyon collapsing the rungs fold down between side walls and ribs and meansfor maintaining ladder in uncollapsed position.

2. A collapsible ladder according to claim 1, in which said channel-likemembers arebraced in opened position by brace pivotally attached at oneend to said channels and opposed end of said brace detachable secured toanother channels.

3. A collapsible ladderin accordance with claim 1, in which said meansfor maintaining ladder in uncollapsed position are cross members. i

1. A folding and collapsible ladder comprising two sections; each section having oppositely facing channel-like members side rails; each of said rails having bottom, outwardly extending side walls and longitudinal extending rib-like member projecting from the bottom and being substantially parallel to side walls; one section of said ladder having one end of each channel-like side rails provided with one wall, part of bottom and rib, extending the distance between adjacent rungs in the other section, beyond the remainder of bottom and other sidewall, the bottoms of unequal length having rung receiving openings therein; rungs pivotally attached to side walls and ribs, adjacent rungs at least in one section attached to side walls and ribs in different planes whereby on collapsing the rungs fold down between side walls and ribs and means for maintaining ladder in uncollapsed position.
 2. A collapsible ladder according to claim 1, in which said channel-like members are braced in opened position by brace pivotally attached at one end to said channels and opposed end of said brace detachable secured to another channels.
 3. A collapsible ladder in accordance with claim 1, in which said means for maintaining ladder in uncollapsed position are cross members. 